Process for breaking petroleum emulsions



Patented Sept. s, 1942 PROCESS FOR BREAKING PETROLEUM EMULSIONS Melvin De Groote, University City, and Bernhard Kelser, Webster Groves, Mo., assignors to Petrolite Corporation, Ltd, Wilmington, Del., a

corporation of Delaware No Drawing. Application March 21, 1941, Serial No. 384,596

11 Claims. (01. 252-340)] The invention relates primarily to the resolution of petroleum emulsions.

The main object of our invention is to provide a novel process for resolving pertl'oleuni emulsions of the water-in-oil type,'that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets ofnaturally occurring waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the-emulsion.

Another object is to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditionsfrom mineral oil, such as crude petroleum and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsificatibn under the conditions just mentioned is'of significant value in removing impurities, particularly inorganic salts, from pipeline oil.

The new chemical compound or composition of matter herein described which is used as the material of the kind herein described, and a polybasic carboxy acid having not over six carbon atoms.

If a hydroxylated material, indicated for the sake of convenience by the formula T.0H, is re-,

acted with a'polybasic carboxy acid, which, similarly, may conveniently be indicated as being of the dibasic type, by the formula HOOC.D.COOH

then the fractional ester obtained by reaction between equimolar quantities may be indicated by the following formula:

HOOCILCOQT the polyalkyleneglycols employed may be indicated by the following formula:

OH (Cal-12110 mH in which m hasits previous significance and n represents a numeral varying from 2 to 4.

Thus, the bulk of the demulsifying materials herein described, may be indicated within certain variations, as hereinafter stated, by the neutral ester derived by esteriflcation of one mole of a lycol of the kind above described, with two moles of a fractional ester of the kind previously described. The formation of the compound may be indicated by the following reaction, although obviously, it is immaterial what particular procedure is employed to produce the particular chemical compound or product:

As indicated previously, the polybasic acids employed are limited to the type having not more than six carbon atoms, for example, oxalic, malonic, succinic, glutaric, and adiplc. Similarly, one may employ acids such as fumaric, maleic, glutaconic, and various others, including citric, malic, tartaric, and the like. The selection of the particular tribasic or dibasic acid employed is usually concerned largely with convenience of manufacture of the finished ester, and also of the price of the reactants. Generally speaking, the higher the temperature employed, the easier it is to obtain large yields of the esterified product. Although oxalic acid is comparatively cheap, it decomposes somewhat readily at slightly above the boiling point of water. For this reason, it is more desirable to use an acid which is more resistant to pyrolysis. Similarly, when a polybasic acid is available in the form of an anhydride, such anhydride is apt to produce the ester with greater ease than the acid itself. For this reason, maleic anhydride is particularly adaptable; and also, everything else considered, the cost is comparatively low on a per molar basis, even though somewhat higher on a per pound basis. Succinic acid or the anhydridehas many of the attractive qualities of maleic anhydride; and this is also true of adipic acid. For purposes of brevity, the

bulk of the compounds hereinafter illustrated heptaethylene and octaethylene glycols, and possibly, minor percentages of the higher homologs. Such glycols represent the upper range of distillaable glycols; and they may be conveniently re- "ferred to as upper distillable ethylene glycols.

There is no particularly good procedure for making a sharper separation on a commercial scale; and it is understood that mixtures of one Or more of the glycols may be em-ployed, as well as a single glycol. As pointed out, it is particularly preferred to employ nonaethylene glycol as commercially available, although it is understood that I this product contains other homologs, as indicated.

Substantially as desirable as the upper distillable polyethylene glycols, are the lower non-distillable polyethylene glycols. These materials are available in the form of a waxy water-soluble material, and the general range may vary some- ;what from decato tetradecaethylene glycol. As

is well understood, the method of producing such' glycols would cause some higher homologs to be formed; and thus, even in this instance there may be present some oxyethylene glycols within the higher range above indicated. One need not point out that these particular compounds consist of mixtures, and that in some instances, particularly desirable esters are obtained by making.

mixtures of the liquid nonaethylene glycol with the soft, waxy, lower non-distillable polyethylene glycols. in the examples will be to nonaethylene glycol; and calculations will be based on a theoretical molecular weight of 414. Actually, in the manufacture the molecular weight of the glycol employed, whether a higher distillable polyethylene glycol, or a lower non-distillable polyethylene glycol, or a mixture of the same, should be determined and reaction conducted on the basis of such determination, particularly in conjunction wit .the hydroXyl or acetyl value.

It has been previously pointed out that it is irmnaterial how. the compounds herein contem- For the sake of convenience, reference plated are manufactured, although we have found it most desirable to react the selected glycol or mixtures of g1; cols with maleic anhydride in a ratio of two moles of the anhydride for one mole of the glycol. Under such circumstances, we have found little tendency to form longer chain polymers; and in factjthe product of reaction, if conducted at reasonably low temperatures, appears to be largely monomeric. For convenience, such intermediate product may then be considered as.

a dibasic or polybasic acid. One mole of the intermediate so obtained is then reacted with two moles of the alcoholic material of the kind subse-' quently described.

It is to be noted, however, that if one prepares a fractional acidic ester, then if two moles of the fractional acidic ester are reacted with one mole of the polyethylene glycol, there is no possibility for the formation of polymeric types of esterification products under ordinary conditions. I

The alcoholic compounds employed as reactants in the manufacture of the present compounds, are materials commonly referred to as high molal alcohols. They are invariably water-insoluble. They contain at least 10 carbon atoms and not more than 32 carbon atoms. They usually contain only one hydroxyl group, but in some instances, as hereinafter indicated, may contain more than one hydroxyl group. Such alcohols are generally obtained by reduction of the corresponding fatty acids or esters thereof. The reaction in its briefest form may be indicated as follows:

R.COOH in the above instance may represent any detergent-forming acid, i. e., any of a number of monocarboxy acids having more than 19 and not over 32 carbon atoms, and characterized by the fact that they combine with alkalies such as caustic soda, caustic potash, ammonia, triethanolamine, and the like, to produce soap or soap-like materials. The best examples are, of course, the higher fatty acids, such as oleic acid, stearic acid, palmitic acid, etc. In addition to the higher fatty acids, other well known members include resinic acids, abietic acids, naphthenic acids, and acids obtained by the oxidation of petroleum hydrocarbons and [commonly referred to as oxidized wax acids. Generally speaking, the higher fatty acids are apt to contain from 12-14 carbon atoms as a lower limit, and from 18-22 carbon atoms as an upper limit. Oxidized waxes may contain as many as 32' carbon atoms. These various acids when unsaturated, may be totally or partially hydrogenated and then converted into the cor-responding alcohol.

The commonest use of high molal alcohols has been their conversion into sulfates or sulfonates. As to patents which specifically enumerate high molal alcohols applicable for use as reactants in the manufacture of the present compound, see the followingf U. S. Patents No. 2,110,848, dated March 8, 1938, De Groote; 2,181,172, dated Oct. 4, 1932, Daimler et al.; 1,916,776, dated July 4, .1938, Steindorff et al.; 2,106,242 and 2,106,243, dated Jan. 25, 1938, De Groote et al.; 2,110,847, dated Mar. 8, 1938, De Groote; 2,000,994, dated May 14, 1935, Schrauth; 2,061,617, 2,061,618, 2,061,619, and 2,061,620, dated Nov. 24, 1936, Downing et al.; 2,171,117., dated Aug. 29, 1939, Schrauth et al.; 2,187,338 and 2,187,339, dated Jan. 16, 1940, Werntz; 1,917,255, dated July 11, 1933, Harris; 2,170,380, dated Aug. 22, 1939, Holsten, and 1,966,187, dated July 10, 1934, Schirm.

Chemically, it is to be noted that these alcohols represent more than one type, i. e., they include aliphatic, alicyclic, aralkyl, etc. Particularly of interest are those derived from naphthenic acids, oxidized wax acids, and by the total or partial hydrogenation of high molal aromatic alcohols or equivalent procedure. Any of the various high molal water-insoluble alcohols occurring naturally in waxes in combined form, may be employed.

As specific examples, mention may be made of v ylic, benzylic, cyclohexylic or naphthylic ethers or glycol or glycerol. Similarly, derivatives of diphenyl, such as hydroxy diphenyl, and the hydroaromatic homologues, are suitable,

The materials herein contemplated may be illustrated further by the following. examples:

Intermediate product, Example 1 One pound mole of nonaethylene glycol is reacted with two pound moles of maleic anhydride' so as to form nonaethylene glycol dihydrogen dimaleate.

Intermediate product, Example 2 A mixture of lower non-distillable polyethylene glycols, representing approximately decato tetradecaethylene glycol, is substituted for nonaethylene glycol in the preceding example.

Intermediate product, Example 3 A 50-5O mixture of nonaethylene glycol and lower non-distillable polyethylene glycols of the kind described in the previous example is substiwater and below the pyrolytic point of the reactants. The products are mixed and stirred constantly during the heating and esterification step. If desired, an inert gas, such as dried nitrogen or dried carbon dioxide, may be passed through the mixture. Sometimes it is desirable to add an esterification catalyst, such as sulfuric acid, benzene sulfonic acid, or the like. the same general procedure as employed in the manufacture of ethylene glycol, dihydrogen diphthalate. See U. S. Patent No. 2,075,107, dated March 30, 1937, to Frasier.

Sometimes esterification is conducted most.

readily in the presence of an inert solvent, that carries away the water of esterification which may be formed, although, as is readily appreciated, such water of esterification is absent when the reaction involves an acid anhydride, such as maleic anhydride, and a glycol. However, if water is formed, for instance, when citric acid is employed, then a solvent such as xylene may be present and employed to carry off the water formed. The mixture of xylene vapors and water vapors can be condensed so that the water is separated. The xylene is then returned to the reactionvessel for further circulation. This is a conventional and well-known procedure and requires no further elaboration.

Composition of matter, Example 1 One pound mole of the intermediate product of the kind described in Intermediate product, Examples 1, 2 and 3, above, is reacted with two This is.

pound moles of decyl alcohol until all carboxyl acidity has disappeared. Time of reaction may vary from a few hours to as much as 20 hours.

Composition of matter, Example 2 Dodecyl alcohol is substituted for decyl alcohol in the preceding example.

Composition of matter, Example 3 Cetyl alcohol is substituted for decyl alcohol in Composition of matter, Example 1.

Composition of matter, Example 4 Tetradecyl alcohol is substituted for decyl al-.

cohol in Composition of matter, Example 1.

Composition of matter, Example 5 Octadecyl alcohol is substituted for decyl alcohol in Composition of matter, Example 1.

Composition of matter, Example 6 Mixed alcohols derived from cocoanut oil fatty acids are substituted for decyl alcohol in Composition of matter, Example 1.-

Composition of matter, Example 7 Oleyl alcohol is substituted for decyl alcohol in Composition of matter, Example 1.

Composition of matter, Example 8 Octadecanediol is substituted for decyl alcohol in Composition of matter, Example 1.

Composition of matter, Example 9 A mixture of naphthenyl alcohols derived from naturally-occurring naphthenic acids and having a carbon atom range approximating 1620 carbon atoms, is substituted for decyl alcohol in Composition of matter, Example 1.

Composition of matter, Example 10 Alcohols derived from abietic acid are substituted for decyl alcohol in Composition of matter, Example 1.

Composition of matter, Example 11 Alcohols derived from oxidized wax acids or having'a carbon atom range of 16-20 carbon atoms are substituted for decyl alcohol in Composition of matter, Example 1.

Composition of matter, Example 12 The same procedure is followed as in Composition of matter, Examples 1-1l, inclusive, except that an intermediate product of the kind exemplified by Intermediate product, Example 4, is substituted for that in Intermediate product, Examples 1, 2 and 3.

Composition of matter, Example 13 The same procedure is followed as in Composition of matter, Examples l-ll, inclusive, except that an intermediate product of the kind exemplified by Intermediate product, Example 5, is substituted for that in Intermediate product, Examples 1, 2 and 3.

Composition of matter, Example 14 The same procedure is followed as in Composition of matter, Examples 1-11, inclusive, except that an intermediate product of the kind exemplified by Intermediate product, Example 6, is substituted for that in Intermediate product, Examples 1, 2 and 3..

Composition of matter, Example 15 The same procedure is followed as in Composition of matter, Examples 1-11, inclusive. ex-

cept that an intermediate product of the kind exemplified by Intermediate product, Example 7, is substituted for that in Intermediate product, Examples 1, 2 and 3.

It is to be noted that this second step is an esterification reaction, and the same procedure is employed as suggested above in the preparation of the intermediate product. Needless to say, any particular method may be used to produce the desired compounds of the kind indicated. In some instances it may be desirable to conduct the esterification reaction in the presence of a nonvolatile inert solvent which simply acts as a diluent or viscosity reducer.

In the preceding examples, attention has been directed primarily to the monomeric form, or at least, to the form in which the bifunctional alcohol, i. e., a glycol, and the polyfunctional acid, usually a bifunctional compound, react to give a chain type compound in which the adjacent acid and glycol nucleus occur as a structural unit. For instance, in the monomeric form this may be indicated in the following manner:

acid glycol acid acid glycol acid glycol acid Similarly, three moles of the glycol and four moles of the acid might tend to give a combination which may be indicated thus:

acid. glycol. acid glycol acid glycol acid Another way of stating the matter is that the composition may be indicated in the following manner:

in which the characters have their previous significance and a: is a relatively small whole number less than 10 and probably less than 5; and in the monomeric form :0, of course, is 1. The limitations on the size of x are probably influenced largely by the fact that reaction leading to further growth is dependent upon random contact.

Some of the products are self-emulsifiable oils, or self-emulsifiable compounds; whereas, others give cloudy solutions or sols; and the most desirable type is characterized by giving a clear solution in water, and usually in the presence of soluble calcium or magnesium salts, and frequently in the presence of significant amounts of either acids or alkalies.

Water solubility can be enhanced in a number of ways which have been suggested by previous manufacturing directions, for instance;

(a) By using a more highly polymerized ethylene glycol;

(b) By using a polymeric form instead of a monomeric form in regard to the unit which forms the chain between the two alcoholic nuc- (0) By using a polybasic carboxy acid of lower molecular weight, for instance, maleic acid, instead of adipic acid;

(d) By using an alcoholic material of lower pounds of the type herein contemplated are limited to the water-soluble type, i. e., those which are self-emulsifying in water or produce a sol or a molecular solution.

Actually, a reaction involving an alcohol and an acid (esterification) may permit small amounts of either one or both of the reactants, depending upon the predetermined proportion, to remain in an unreacted state. In the actual preparation of compositions of the kind herein contemplated, any residual acidity can be.removed by any suitable base, for instance, ammonia, triethanolamine, or the like, especially in dilute solution. Naturally, precaution should be taken so that neutralization takes place without laponification or decomposition of the ester. In some cases there is no objection to the presence or" the acidic group. Indeed, if a tribasic acid be employed in such a manner as to leave one free carboxyl group, then it is usually desirable to neutralize such group by means of a suitable basic material.

In the hereto appended claims, reference to a neutral product refers to one in which free carboxylic radicals are absent.

Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, of after dilution with any suitable solvent, such as water; petroleum hydrocarbons such as gasoline, kerosene, stove oil; a coal tar product such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents, such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may be employed as diluents. Similarly, the material or materials herein described, may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents, provided that such compounds are compatible. They will be compatible with the hydrophile type of solvent in all instances. Moreover, said material or materials may be used alone, or in admixture with other suitable well known classes of demulsifying agents.

It is well known that conventional demulsifying agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both oil and water solubility. Sometimes they may be used in a form which exhibits relatively limited oil solubility. However, since such reagents are sometimes used in a ratio of 1 to 10,000 or 1 to 20,000 or even 1 to 30,000 such an apparent insolubility in oil and water is not significant, because said reagents undoubtedly have solubility within the concentration employed. This same fact is true in regard to the material or materials herein described, except that they are invariably water-soluble.

We desire to point out that the superiority of the reagent or demulsifying agent contemplated in our herein described process for breaking petroleum emulsions, is based upon its ability to molecular weight, for instance, decyl alcohol, in-

stead of octadecyl alcohol.

In any event, it is to be noted that the comtreat certain emulsions more advantageously and at a somewhat lower cost than is possible with other available demulsifiers, or conventional mixtures thereof. It is believed that the particular demulsifying agent or treating agent herein described will find comparatively limited application, so far as the majority of oil field emulsions are concerned; but wehave found that such a demulsifying agent has commercial value, as it will economically break or resolve oil field emulsions in a number of cases which cannot be treated as easily or at so low a cost with the demulsifying agents heretofore available.

In practising our improved process for resolving petroleum emulsions of the water-in-oil type, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various ways, or by any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used either alone, or in combination with other demulsifying procedure, such as the electrical dehydration process.

The demulsifier herein contemplated may be employed in connection with what is commonly known as down-the-hole procedure, i.' e., bringing the demulsifier in contact with the fluids of atoms; and (B) a-polvbasic carboxy acid having not more than 6 carbon atoms; and the ratio of the esterifying reactants being within the range of more than 1 and not over 2 moles of the polybasic acid foreach mole of the glycol.

3. A process for breaking petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a neutral water-soluble esterification product derived-by reaction between one mole of a polybasic compound and two moles of a high molal water-insoluble alcohol having at least carbon atoms and not more than 22 carbon atoms; the polybasic compound being the esterification product of (A) a polyalkylene glycol having at least ,7 and not more than 1'7 ether linkages, and the alkylene radical thereof con taining at least 2 and not more than 6 carbon atoms; and (B) a polybasic carboxy acid having the well at the bottom of the well, or at some point prior to their emergence. This particular type of application is decidedly feasible when the demulsifier is used in connection with acidification of calcareous oil-bearing strata, especially if suspended in or dissolved in the acid employed for acidification.

It will be apparent to those skilled in the art that residual carboxyl acidity can be eliminated by esterification with a low molal alcohol, for instance, ethyl, methyl, or propyl alcohol, by conventional procedure, so as to give a substantially neutral product. The introduction of such low molal hydrophobe groups does not seriously affeet the solubility, and in some instances gives increased resistance, to soluble calcium and magnesium salts, for such property is of particular value. Usually, however, neutralization with a dilute solution of ammonia or the like is just as practicable and less expensive.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

l. A process for breaking petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a water-soluble esterification product derived by reaction between one mole of a polybasic compound and two moles of a high molal water-insoluble alcohol having at least 10 carbon atoms and not more than 32 carbon atoms; the polybasic compound being the esterification product of (A) a polyalkylene glycol having at least '7 and not more than 17 ether linkages, and the alkylene radical thereof containing at least 2 and not more than 6 carbon atoms; and (B) a polybasic carboxy acid having not more than 6 carbon atoms; and the ratio of the testerifying reactants being within the range of more than 1 and not over 2 moles of the polybasic acid for each mole of the glycol.

2. A process for breaking petroleum emulsions of the water-inoil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a water-soluble esterification product derived by reaction between one moleof a polybasic compound and two moles of a high molal water-insoluble alcohol having at least 10 carbon atoms and not more-than 22 carbon atoms; the polybasic compound being the esterification product of (A) a polyalkylene gly col having at least 7 and not more than 17 ether linkages, and the alkylene radicalthereof containing at least 2 and not more than 6 carbon not more than 6 carbon atoms; and the ratio of the esterifying reactants being within the range of more than 1 and not over 2 moles of the polybasic acid for each mole of the glycol.

4. A process for breaking petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a neutral water-soluble esterification product derived by reaction between one mole of a dibasic compound and two moles of a high molal water-insoluble alcohol having at least 10 carbon atoms and not more than 22 carbon atoms; the dibasic compound being the esterification product of (A) a polyalkylene glycol having at least '7 and not more than 17 ether linkages, and the alkylene radical thereof containing at least 2 and not more than 6 carbon atoms; and (B) a dibasic carboxy acid having not more than 6 carbon atoms; and the ratio of the esterifying reactants being within the range of more than 1 and not over 2 moles of the dibasic acid for each mole of the glycol.

5. A process for breaking petroleum emulsions of the Water in-oiI type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a neutral water-soluble esterification product derived by reaction between one mole of a dibasic compound and two moles of 'a high molal water-insoluble alcohol having at least 10 carbon atoms and not more than 22 carbon atoms; the dibasic compound being the esterification product of (A) a polyethylene glycol having at least '7 and not more than 1'7 ether linkages; and (B) a dibasic carboxy acid having not more than 6 carbon atoms; and the ratio of the esterifying reactants being within the range of more than 1 and not over 2 moles of the dibasic acid for each mole of the glycol.

6. A process for breaking petroleum emulsions of .the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a neutral water-soluble esterification product derived by reaction between one mole of a dibasic compound and two moles of a high molal water-insoluble aliphatic alcohol having at least 10,and not more than 18 carbon atoms; the dibasic compound being the esterification product of (A) a polyethylene glycol having at least? and not more than 17 ether linkages; and (B) a dibasi c carboxy acid having not more than 6 carbon atoms; and the ratio of the esterifying reactants being within the range of more than 1 and not over 2 moles of the dibasic acid for each mole of the glycol.

'7. A process for breaking petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a neutral water-soluble chemical compound of the formula type:

TOOC.D.COO (C2H40) mC2H4OOC.D.COO IT in which T is a radical derived by dehydroxylation of a high molal, water-insoluble aliphatic alcohol having at least 10 and not more than 18 carbon atoms; O0C.D.CO0 is the acid radical derived from a dibasic acid by removal of the acidic hydrogen atoms; said acid radical having not over 6 carbon atoms; m represents a numeral varying from 7 to 12; and :z: is a small whole number less than 10.

8. A process for breaking petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a neutral water-soluble chemical compound of the formula type:

TOOC.D.COO (C2H40) mC2H4OOC.D.COO.T

in which T is a radical derived by dehydroxylation of a high molal, water-insoluble aliphatic alcohol having at least 10 and not more than 18 carbon atoms; OOC.D.CO0 is the acid radical derived from a dibasic acid by removal of the acidic hydrogen atoms; said acid radical having not over 6 carbon atoms; and m represents a numeral varying from '7 to 12.

9. A process for breaking petroleum emulsions of thewater-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a neutral water-soluble chemical compound of the formula type:

TOOC.D.COO(C2H4O) mC2H4OOC.D.COO.T

in which T is a radical derived by dehydroxylation of a high molal, water-insoluble aliphatic alcohol having at least 10 and not more than 18 carbon atoms; OOC.D.CO0 is the acid radical derived from maleic acid by removal of the acidic hydrogen atoms; and m represents a numeral varying from 7 to 12.

10. A process for breaking petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a neutral water-soluble chemical compound of the formula type:

in which I is a radical derived by dehydroxylation of a high molal, water-insoluble aliphatic alcohol having at least 10 and not more than 18 carbon atoms; OOC.D.COO is the acid radical derived from succinic acid by removal of the acidic hydrogen atoms; and m represents a numeral varying from 7 to 12.

11. A process for breaking petroleum emulsions of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsitying agent comprising a neutral water-soluble chemical compound of the formula type:

TOOC.D.COO (C2H4O) mC2H4OOC.D.COO.T in which T is a radical derived by dehydroxylation of a high molal, water-insoluble aliphatic.

alcohol having at least 10 and not more than 18 carbon atoms; OOC.D.COO is the acid radical derived from adipic ,acid by removal of the acidic hydrogen atoms; and m represents a numeral varying from 7 to 12.

MELVIN DE cmoo'ra. BERNHARD KEISER. 

